By Alex MacDonald

LONDON--India-focused natural resources company Vedanta Resources PLC (VED.LN) Friday reported lower earnings during its third-quarter due to lower profitability from its oil and gas division and a slump in the profitability of its Zambian copper operations.

The producer of commodities ranging from zinc to copper, iron ore and aluminum, said earnings before interest, taxes, depreciation and amortization, or Ebitda, dropped 11% to $1.02 billion in the three months ended Dec. 31, compared with the same period a year before. Revenue rose 1% to $3.36 billion.

The Ebitda of its majority-owned Cairn India Ltd. (532792.BY) oil and gas company fell 44% after the unit was hit by the slump in the price of oil and a 2% drop in oil and gas production during the period.

Meanwhile, lower copper price and higher production costs saw revenues at its Zambian copper operations fall by 5%. Vedanta said the decision by the Zambian government to increase royalty rates from the start of the year would hit its majority-owned Konkola Copper Mines PLC unit by around $15 million in the fourth quarter, equal to about all of its Ebitda for the first nine months of its fiscal year.

Vedanta swung to a small profit at its iron ore division from the sale of additional iron ore, even though production was crimped by the suspension of its operations in India's key iron-ore producing states of Goa and Karnataka. The company said it expects to begin producing iron ore from Karnataka by February and from Goa from the start of April onwards. Iron ore production in both states had been suspended due to a mining ban.

The company said its net debt dropped to $8.8 billion at the end of December from $9 billion at the end of September.

-Write to Alex MacDonald at alex.macdonald@wsj.com

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